Serine proteases represent a broad class of proteolytic enzymes that are involved in physiological processes such as blood coagulation, complement activation, phagocytosis and turnover of damaged cell tissue. Human chymase (EC.3.4.21.39) is a glycosylated monomeric chymotrypsin-like serine protease (MW=30 kDa) localized mainly in mast cell secretory granules. Chymase is thought to have a variety of functions, including degradation of extracellular matrix proteins, cleavage of angiotensin I to angiotensin II (except in the rat), and activation of matrix proteases and cytokines. Endogenously, chymase is regulated by the serpins α1-antichymotrypsin and α1-proteinase.
Although the precise patho-physiological roles of chymase have yet to be determined, chymase has been implicated in microvascular leakage, neutrophil accumulation, the stimulation of mucus secretion, and the modulation of cytokines. A potent, chymase-selective inhibitor may be indicated in mast cell-mediated diseases such as asthma, pulmonary inflammation, and chronic obstructive pulmonary diseases (COPD). Because chymase can play a role in the generation of cardiac and vascular wall angiotensin II, an inhibitor may have potential use as an antihypertensive treatment for vascular wall injury and inflammation (atherosclerosis/restenosis), as well as cardiac hypertrophy. Thus, small molecule inhibitors of chymase are likely to represent useful therapeutic agents.
U.S. Pat. No. 5,508,273 to Beers, et al. and Bioorganic & Med. Chem. Lett., 1995, 5 (16), 1801-1806 describe phosphonic acid compounds useful in treating bone wasting diseases. In particular, 1-napthylmethylphosphonic acid derivatives have been described as osteoclastic acid phosphatase inhibitors of the formula:

Accordingly, it is an object of the present invention to provide phosphonic acid and phosphinic acid compounds that are serine protease inhibitors, in particular, inhibitors of chymase, useful for treating inflammatory and serine protease mediated disorders. It is another object of the invention to provide a process for preparing phosphonic or phosphinic acid compounds, compositions, intermediates and derivatives thereof. It is a further object of the invention to provide methods for treating inflammatory and serine protease mediated disorders.